Is Mario more than a century old or did Nintendo just retcon SMG?

[Cheebee]

Khuutra said:
Nintendo really doesn't care about the story. They come up with the gameplay, then a scenario. Continuity is, at best, a tertiary concern (lower if you consider level design separate from gameplay).

This. That's also why all Zelda-timeline debates are useless. Nintendo always implements the scenario later, after the gameplay mechanics and levels have been constructed, Miyamoto said so on numerous occasions during interviews.